Australopithecus
I agree with your scepticism.
Of course, what we don't know is how the guy on the rig guestimated the 50-70km distance he gave, or what the guestimated altitude was.
Estimating distance and altitude at night is very difficult, so I would take those numbers with a bit of a pinch of salt.
Of course, it would still be nigh on impossible to spot even a burning aircraft at anything like 380-odd kilometres. Even assuming perfect conditions, it would be nothing more than a faint pin-prick of light in the sky, so quite how one would deduce it to be a burning aircraft is another question!